Instructiont--->Bitlogic--> -|P|-
Instructiont--->Bitlogic--> -|N|-
以下是帮助中的材料：
The Positive Transition (EU) contact allows power to flow for one scan for each off-to-on transition.The Negative Transition (ED) contact allows power to flow for one scan for each on-to-off transition.In LAD, the Positive and Negative Transition instructions are represented by contacts.In FBD, the instructions are represented by the P and N boxes.In STL, the Positive Transition contact is represented by the Edge Up instruction. Upon detection of a 0-to-1 transition in the value on the top of the stack, the top of the stack value is set to 1; otherwise, it is set to 0.In STL, the Negative Transition contact is represented by the Edge Down instruction. Upon detection of a 1-to-0 transition in the value on the top of the stack, the top of the stack value is set to 1; otherwise, it is set to 0. For runtime editing (when you edit your program in RUN mode), you must enter a parameter for the Positive Transition and Negative Transition instructions. Refer to Program Edit in RUN Mode for more information about editing in RUN mode.
